Clutter Suppression in ISAC Systems With Compound Reconfigurable Antenna Arrays

Liu M, Li M, Liu R, Liu Q, Lee Swindlehurst A (2026)

Publication Type: Journal article

Publication year: 2026

Journal

IEEE Transactions on Wireless Communications Institute of Electrical and Electronics Engineers (IEEE)

Book Volume: 25

Pages Range: 24160-24175

DOI: 10.1109/TWC.2026.3737071

Abstract

Integrated sensing and communication (ISAC) systems often suffer severe performance degradation due to strong clutter echoes, and spatial-only beamforming may be inadequate under practical array-size and aperture constraints. This paper addresses clutter suppression in ISAC by leveraging compound reconfigurable antenna (CRA) arrays, which simultaneously enable dynamic adjustment of both radiation patterns and polarization states, thus substantially expanding the degrees of freedom available in the electromagnetic (EM) domain. To obtain physically realizable EM-domain responses, we model a pixel antenna in CST Microwave Studio and use the simulated responses to construct an EM-mode dictionary for different reconfigurable modes. We develop a unified compound channel model that integrates virtual angular-domain responses, spatial propagation, and polarization rotation/depolarization. Leveraging statistical information about target and clutter covariances, we formulate a joint EM-domain and baseband-domain optimization aimed at maximizing the radar signal-to-clutter-plus-noise ratio (SCNR). The formulation also enforces multi-user downlink signal-to-interference-plus-noise ratio constraints, a total transmit-power budget, and finite-dictionary EM-mode selection. The resulting nonconvex mixed-integer problem is tackled by an alternating algorithm that combines fractional programming and majorization-minimization with second-order cone programming-based updates and a penalty relaxation for mode selection. Extensive simulations in QuaDRiGa-based channel environments are conducted using the CST-generated EM-mode dictionary. The results validate the effectiveness of the proposed CRA array design, demonstrating up to 9 dB SCNR improvements over conventional beamforming methods relying solely on baseband-domain optimization and confirming the substantial benefits of fully exploiting EM-domain reconfigurability for clutter-rich ISAC scenarios.

Authors with CRIS profile

Rang Liu Lehrstuhl für Digitale Übertragung (IDC)

Involved external institutions

Dalian University of Technology (DUT) / 大连理工大学 CN China (CN) University of California Irvine US United States (USA) (US)

How to cite

APA:

Liu, M., Li, M., Liu, R., Liu, Q., & Lee Swindlehurst, A. (2026). Clutter Suppression in ISAC Systems With Compound Reconfigurable Antenna Arrays. IEEE Transactions on Wireless Communications, 25, 24160-24175. https://doi.org/10.1109/TWC.2026.3737071

MLA:

Liu, Mengzhen, et al. "Clutter Suppression in ISAC Systems With Compound Reconfigurable Antenna Arrays." IEEE Transactions on Wireless Communications 25 (2026): 24160-24175.

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